Even I have trouble with this one

[Don.F.Broadus at ucm.com]

I think you are referring to the all aluminum ZL1 and that was a 427.
Reynolds aluminum cast the blocks and winters foundry cast the heads. The
ZL1 engine was about a $2500 option and very few  were ordered. GM has just
released an improved version of this engine that you can buy at any dealer.
CanAm racing was the driving force for GM to develop this engine, most were
punched out to 488 and 502 cubic inches for competition.  If you want more
info on the LT5
Order the book ' Heart of the beast' from your local GM dealer, I don't have
the part number in front of me but I purchased mine about a year ago, cost
$40.   

                                                                        Don




	-----Original Message-----
	From:	Bob McElroy [SMTP:rmcelroy at cfu-cybernet.net]
	Sent:	Wednesday, October 07, 1998 1:59 PM
	To:	diy_efi at efi332.eng.ohio-state.edu
	Subject:	RE: Even I have trouble with this one

	Actually, I believe the original ZR1 Corvette had a big-block Chevy
	(454?) under the hood.  For those that aren't familiar, the original
ZR1
	Corvette was built back in the heyday of the musclecar, the late
	60's/early 70's (off the top of my head, I don't recall the actual
model
	years for the original ZR1.)  As with most of those cool sounding
names
	(Z28, LE1, LT5, LS6, ZR1, LS1), they are Chevy's ordering code for
the
	specific equipment.

	The more modern ZR1 used a Lotus-designed engine that was cast &
	assembled by Mercury Marine (hmm, fiberglass body and an engine
built by
	a boat company;  was the ZR1 actually a "boat"?)  The LT5 engine had
	dual cams per cylinder bank, 4 valves per cylinder, for a total of
32
	valves.  To feed those 16 intake valves, it did indeed have 16 tuned
	individual intake runners.  However, only 8 of the runners were
	functional at lower engine speeds (again, I don't recall the actual
	transition point, but I think it was between 2500 - 3500 RPM.)  This
was
	done to enhance low-end drivability without affecting top-end power.
	From what I have heard/read, the system did work pretty well, but it
was
	a VERY expensive way to get more power.

	Bob McElroy

	PS - The more I think about, the original ZR1 may actually have been
a
	small-block Chevy (350).  I think the big-block version was actually
	called a ZR2.


	-----Original Message-----
	Aren't all the ZR-1 corvettes the overhead cam jobs?.  Aren't
	all these the 16 injector dual runner intakes?.